Isolated Prompt Photon Production

Abstract

We show that the conventionally defined partonic cross section for the production of isolated prompt photons is not an infrared safe quantity. We work out the case of $e^+e^- \to \gamma + X$ in detail, and we discuss implications for hadron reactions such as $p \bar{p} \to \gamma + X$.Comment: 8 pages, latex2e, 2 figures, uses Moriond.sty; Invited paper presented by E. L. Berger at the XXXIInd Rencontres de Moriond, QCD and High Energy Hadronic Interactions, Les Arcs, Savoie, France, March 22 - 29, 199